Make Haste with Waste
by Jim Lane (Biofuels Digest) … (W)hen you compare them to homogenized, uniform, high-yield, purpose-grown energy crops. residues may be queer, but they are here. Not only available, but reliable, you can count on the fact that they will not so easily slip into the food stream. And, affordable — today, that is, and especially compared to traditional agricutural feedstocks that supply the food, feed and fiber markets.
Perhaps most importantly, they are sustainable. As residues, they do not require land use change to be tapped as a feedstock, reducing the carbon footprint in the journey towards low-carbon fuels. Nor do they induce indirect land use change, so far as common sense would tell us.
The hard data on ag residues
The DOE Billion Ton Update tells us that, at $60 per ton in constant 2011 dollars, there are 160 million dry tons of corn stover and agricultural process residues & wastes available in the US. At $80 per ton, there is 105 million dry tons of urban wood waste, mill residues and “primary forest residues” available to the market.
So, let’s consider 80 percent of that to be tappable in a reliable sense with affordable logistics — which would leave us with a market of 210 million dry tons of biomass available to the market, today, at a blended price of $67 per ton. That’s 3.4 cents per pound in feedstock cost.
A conversion technology that can produce 50 gallons per ton in the diesel and jet fuel range — that’s Fulcrum Bioenergy’s publicly-shared yield — well, that gives us 10.5 billion gallons of fuel, from that resource.
Waste oils and greases as a feedstock
How much is there? WaterWorld reports:
Over 4 billion gallons of waste grease per year is generated in the United States, presenting costly challenges to wastewater treatment systems. (That equates to around 28 million tons). Local governments spend over $25 billion annually maintaining sewer systems, necessitating more effective strategies to contain the financial and environmental impacts caused by sanitary sewer overflows (SSO) and combined sewer overflows (CSO). In addition, many States are placing stricter requirements on industries to resolve issues with waste fats, oils and greases (FOG) before wastewater enters the sewer system, adding logistical and technological challenges to those faced by waste generators.
Mark Jekanowski of Informa Economics writes:
Livestock slaughter by-products, restaurant grease, and scraps from grocery stores and butcher shops comprise the three primary raw material streams processed by renderers. The total volume of these raw materials processed is estimated at 48.32 billion pounds in 2010, about 91 percent of which consists of slaughter by-products, five percent is restaurant grease, and four percent is waste from grocery stores and butcher shops.
So, the numbers here suggest that there’s a 41 billion set of RINs out there — to add to the 18 billion generated today. Given that a small amount of waste fats and greases are being already used for biodiesel and renewable diesel production, consider that there’s something like 56 billion RINs out there in US renewable fuels, from these sources.
And, we haven’t considered as much as another billion RINs available from conversion of biogas into renewable fuels, from dairy and other animals wastes and manures. READ MORE